55 years ago today, the United States tested a hydrogen bomb over Namu island, in the Bikini Atoll, Pacific Ocean. The 15 megaton bomb exploded at 15,000 feet, causing a four-mile fireball, 500 times brighter than the Sun.

It was the first airborne test of the hydrogen bomb—created in 1951 by Edward Teller and Stanisław Ulam—and yet another nuclear test of the long Bikini Atoll series. By then, another kind of atomic weapon was already being tested in beaches all around the world, one of the most fascinating pieces of garment ever devised by humankind: The bikini.

The origin of the bikini

It was in May 1946 when Louis Réard—a French car engineer who at the time was running his mom's lingerie shop in Paris—introduced two small pieces of clothing, advertising them as "the smallest bathing suit in the world." Simultaneously and unknowingly, fashion designer Jacques Heim was working on a similar design.

Réard named his invention the bikini because of the Bikini Atoll nuclear tests. He thought that everyone would be shocked by the risqué display of curves and belly buttons. He was right. During many years, the bikini caused more surprise than any of the nuclear tests conducted by the United States and the Soviet Union. The joke at the time was that that the "bikini" split the "atom", because it was introduced right after a tiny single-piece bathing suit called the Atome.

The bikini was so explosive that even American bathing suit queens disapproved, as the Los Angeles Times writes in 1949:

The bathing beauty queen-blond Bebe Shopp, 18, of Hopkins, Minn.-got an enthusiastic welcome in Paris, but she said she hasn't changed her mind about French swim suits. ... 'I don't approve of Bikini suits for American girls,' Bebe told her French interviewers. 'The French girls can wear them if they want to, but I still don't approve of them on American girls.

Little she could imagine the tiny g-strings to be used only a decade later.

The real origin of the bikini

But while we should all rejoice for the invention of the bikini, the car engineer and the fashion designer were only rediscovering it. In fact, the two piece bathing suit was already being used in the greco-roman world, back in the third century AD.

This mosaic—discovered in Villa Romana del Casale, Sicily—is good proof of that. Its thousands of colored tiles show women in bikini playing and exercising by the beach. Habemus Pamela Anderson.

This wasn't the only display of bikinis at the time. In Pompeii, archeologists discovered several statues of the goddess Venus wearing a bikini. And only six hundred years before this, the greek philosopher Democritus formulated his atomic theory of the cosmos, which explained that our world was made of tiny, invisible particles that were in constant motion.